Flexibility and compact multi-stream heat exchange process with cryogenic heat exchange network (CHEN) and liquid nitrogen regeneration refrigeration system (LN2 ReS) was proposed for onboard liquefied natural gas (LNG) reliquefaction. LNG circulates heat exchange with liquid nitrogen through recuperator, precooler, and subcooler successively in the CHEN to become supercooled LNG. Then it sprayed from the upper part into the storage tank to cool its boil off gas (BOG). To achieve the purpose of BOG reliquefaction in the tank. Based on the reverse Brayton nitrogen cycle, the nitrogen is regenerated into liquid nitrogen by an economizer, compressor, cooler, and expander in turn for storage and the next heat exchange. Measured the heat transfer result of 20 kW cold capacity, and found that the proposal has the characteristics of compact structure, no freezing, simple control logic, efficient pre-cooling liquefaction, etc. It only needs to control the design freedom of the flow rate of the LN2 ReS, which can be adapted to the LNG reliquefaction process. Besides, the exergy loss of the proposed CHEN accounts for 30.3% of the total, which is less than the proportion of the LN2 ReS. After process calculation, experimental case study, and exergy loss analysis, it proves the feasibility of the proposal and is particularly suitable for new energy ships.

提出了具有低温热交换网络（CHEN）和液氮再生制冷系统（LN2 ReS）的灵活性和紧凑的多流热交换工艺，用于船载液化天然气（LNG）的再液化。LNG先后在CHEN中通过换热器，预冷器和过冷器与液氮循环换热，成为过冷LNG。然后，它从上部喷到储罐中，以冷却其蒸发气体（BOG）。以达到BOG在罐中重新液化的目的。基于反向布雷顿氮循环，氮通过节热器，压缩机，冷却器和膨胀器再生为液氮，依次用于存储和下一次热交换。测量了20 kW冷容量的传热结果，发现该建议具有结构紧凑的特点，无需冻结，简单的控制逻辑，有效的预冷液化等。只需控制LN2 ReS流量的设计自由度即可适应LNG再液化过程。此外，拟建CHEN的火用损失占总数的30.3％，小于LN2 ReS的比例。经过过程计算，实验案例研究和火用损失分析，证明了该方案的可行性，特别适用于新能源船。